Unfortunately, I can't really explain it that well, but AB is 6, and A'B' is 2.
6 / 3 = 2
BC is 3, and B'C' is 1.
3 / 3 = 1
Therefore the dilation factor would be 1/3.
Hope this helps! :)
6 months -> 18 books
1 month -> 18/6 = 3 books
15 months -> 3 x 15 = 45 books
Answer:
-14.50, -8/4, 4.2, 15/2, 12.072, 12.25